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C. Ferreira, E. Lynch, A. O’Herlihy et al.

The rapid growth of the dairy sector requires advanced monitoring tools to ensure sustainable practices that benefit the environment, economy, and human health. Current monitoring devices often lack multi-parametric capabilities, limiting their ability to provide comprehensive data on critical chemical and biochemical parameters. To address this challenge, this work presented the integration of a real-time multi-parametric device with sensors for pH, temperature, nitrate, and nitrite, providing a comprehensive solution to dairy cattle health monitoring. This solution included an electrochemical platform, Portable Unit for Lab-on-Site Electrochemistry (PULSE), and an application for data processing and display. In-house fabricated flexible gold-printed electrodes demonstrated accurate detection of nitrite and nitrate when integrated with the PULSE, achieving sensitivities of 6.32 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>A/ppm/<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>cm</mi><mn>2</mn></msup></semantics></math></inline-formula> in artificial interstitial fluid and 1.92 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>A/ppm/<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>cm</mi><mn>2</mn></msup></semantics></math></inline-formula> in phosphate buffered saline, respectively. The PULSE achieved 65.83% and 58.3% lower limits of detection in phosphate buffered saline than a benchtop potentiostat, for nitrate and nitrite, respectively, along with a 24.5% increase in nitrite sensitivity, enhancing its ability to detect lower analyte concentrations. pH sensing was carried out with a commercial screen-printed electrode coated with a layer of iridium oxide. The pH was tested in ruminal complex fluid, obtaining a pH sensitivity of −59.63 mV/pH and an accuracy of 98.9%. These findings highlighted the potential of this technology as an effective tool for dairy cattle health monitoring and its deployment in real-world scenarios.

N. Tapia, N. Tapia, L. Endres et al.

<p>In natural ecosystems, phosphorus cycling regulates terrestrial productivity and may respond to climate variations. Seasonal to several year monitoring studies capture the short-term controls on P release but may miss longer term feedbacks. There is an important observational gap of the centennial to millennial scale response of the P cycle to climate oscillations. Cave carbonates such as stalagmites and flowstones, which precipitate from infiltrating groundwater, may record past changes in P loss on these timescales. Here, we examine trends in <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">P</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="7bc88ad49366bea4c9892c3f4c80ba0d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-6861-2025-ie00003.svg" width="30pt" height="14pt" src="bg-22-6861-2025-ie00003.png"/></svg:svg></span></span> ratios in four coeval stalagmites from coastal caves in NW Iberia during two climate transitions, the Penultimate Glacial Maximum through the Last Interglacial (145 to 118 kyr BP) and an intermediate glacial climate state interrupted by an abrupt cooling event of the Greenland Stadial 22 (92 to 80 kyr BP). We conduct sensitivity tests with a model to assess the degree to which drip water pH and in-cave drip water chemical evolution could affect the stalagmite <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">P</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="decca7a975cb3cfb827a54e989e1548e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-6861-2025-ie00004.svg" width="30pt" height="14pt" src="bg-22-6861-2025-ie00004.png"/></svg:svg></span></span> record. Both during the last deglaciation and during Greenland Stadial 22, we find large (3–10-fold) transient increases in stalagmite <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">P</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="229cc75daaf45f204e59bb17f41ecd96"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-6861-2025-ie00005.svg" width="30pt" height="14pt" src="bg-22-6861-2025-ie00005.png"/></svg:svg></span></span> at the onset of abrupt cooling events and during the rapid recovery from some events. These increases are much larger than can be explained by variations in P incorporation due to drip water pH or in-cave chemical evolution and likely reflect significantly increased drip water <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">P</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="0e02b4b0fb453eba4d365b8aa563d707"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-6861-2025-ie00006.svg" width="30pt" height="14pt" src="bg-22-6861-2025-ie00006.png"/></svg:svg></span></span> ratios at the onset and end of abrupt stadial events. Two climatic factors may contribute to this increased leaching. First, soil temperatures may reach minimum values during these transition states, if the temperature minimum leads to increased thickness and duration of snow cover which raises soil temperatures. Minimum winter soil temperature suppresses microbial recycling of P. Second, the transitions into and out of stadial events may feature the highest frequency of freeze-thaw events which change the physical soil structure and lead to stronger spring flushing of P. Additionally, during cooling, reduced soil respiration rates may raise the pH of soil water and lead to increased mobility of P bound to soil minerals.</p>

Chi-Wen Hsieh, Zih-Shiuan Chiou, Chuan-Pin Lee et al.

The safety and storage of nuclear disposal plays a critical challenge in the utilization of radiology applications such as for nuclear medicine, radiotherapy, nuclear energy, particularly concerning the environmental behavior of radio-materials. One of the most concerning materials is radiocalcium due to its physical and chemical mechanism and half-life period. In this study, several minerals were collected, including basalt, argillite, mudrock and granite for the batch tests. In analysis stage, X-ray diffraction and absorption spectroscopy were used for radio-Cs LIII-edge adsorption study. The batch test process shows that basalt, argillite, and mudrock exhibited strong adsorption effectiveness for Cs, with distribution coefficient values (<inline-formula> <tex-math notation="LaTeX">$\ge 700$ </tex-math></inline-formula> mL/g). In contrast, granite from two different locations showed lower distribution coefficient values (&#x003C;15 mL/g) after adsorption, with pH also affecting the adsorption efficiency. The coordination number ratio confirmed the adsorption mechanisms: basalt and argillite exhibited inner-sphere (IS) complexation, granite showed a transition from ion exchange to IS complexation due to pH effects, and mudrock exhibited IS complexation after Cs+ dehydration. A novel EXAFS fitting strategy is proposed to deliver reasonable fitting parameters. Moreover, a 2D wavelet transform with XANES could deliver another viewpoint of the adsorption mechanisms. Based on the comparison with adsorption parameters of the standard CsNO3 sample, an iterative check algorithm is proposed then to yield the reasonable outcomes. The preliminary results found that the hydration layer adsorption mechanism of argillite and mudrock are similar to CsNO3, while granite-W and mudrock displayed similar structural information for outer-sphere (OS) complexes, indicating IS complexation caused by Cs+ dehydration.

C. P. Slomp, C. P. Slomp, M. Hermans et al.

<p>Since the discovery of cable bacteria more than a decade ago, these multicellular, filamentous sulfur-oxidizing bacteria have been found in a range of sedimentary environments. However, their abundance, diversity, and activity in continental margin sediments overlain by oxygen-deficient waters at water depths of <span class="inline-formula"><i>&gt;</i></span> 100 m remain poorly known. Here we address this by studying five basins along the coasts of California and Mexico. All sediments are organic carbon rich (2.5 wt %–7.5 wt %) and characterized by active iron and sulfur cycling. Nitrate is present in the bottom water at all sites. Results of fluorescence in situ hybridization (FISH) indicate a low areal abundance of cable bacteria (0.2 to 19 m cm<span class="inline-formula">⁻²</span>) in sediments of the hypoxic San Clemente, Catalina, and San Pedro basins and the anoxic San Blas basin. In the anoxic Soledad basin, in contrast, we found abundant cable bacteria near the sediment surface (129 m cm<span class="inline-formula">⁻²</span>). DNA amplicon sequencing detected cable bacteria reads in sediments of the hypoxic San Pedro basin and the anoxic Soledad and San Blas basins. Phylogenetic analysis indicated that the diversity of the amplicon sequence variants (ASVs) was spread across the <i>Candidatus</i> Electrothrix lineage, including multiple ASVs closely related to <i>Electrothrix gigas</i>, a recently discovered species of giant cable bacteria. Additionally, multiple sequences retrieved from the Soledad and San Blas basins revealed affiliation with a clade sister to <i>Electrothrix</i>, hypothesized as a novel genus, suggesting possible relic or novel adaptations of cable bacteria to these anoxic and nitrogenous environments. The areal abundance of cable bacteria was negatively related to sediment Fe <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="57ee8123d9c9aefcf23d9c7f6463c158"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4885-2025-ie00001.svg" width="8pt" height="14pt" src="bg-22-4885-2025-ie00001.png"/></svg:svg></span></span> S ratios, suggesting a control by sulfide availability. However, free sulfide in the porewater was only detected at the anoxic Soledad site. Micro-profiling of pH and electric potential points toward a lack of cable bacteria activity at the time of sampling, possibly due to a limitation by a suitable electron donor and/or acceptor. Periodically enhanced organic matter input and associated sulfate reduction and/or inflows of oxic water could alleviate the deficiency, creating the observed niche for diverse cable bacteria.</p>

N. Metzl, C. Lo Monaco, C. Leseurre et al.

<p>The temporal variation of the carbonate system, air–sea CO<span class="inline-formula">₂</span> fluxes, and pH is analyzed in the southern Indian Ocean, south of the polar front, based on in situ data obtained from 1985 to 2021 at a fixed station (50°40<span class="inline-formula">^′</span> S–68°25<span class="inline-formula">^′</span> E) and results from a neural network model that reconstructs the fugacity of CO<span class="inline-formula">₂</span> (<span class="inline-formula"><i>f</i>CO₂</span>) and fluxes at monthly scale. Anthropogenic CO<span class="inline-formula">₂</span> (C<span class="inline-formula">_ant</span>) is estimated in the water column and is detected down to the bottom (1600 m) in 1985, resulting in an aragonite saturation horizon at 600 m that migrated up to 400 m in 2021 due to the accumulation of C<span class="inline-formula">_ant</span>. At the subsurface, the trend of C<span class="inline-formula">_ant</span> is estimated at <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M12" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">0.53</mn><mo>±</mo><mn mathvariant="normal">0.01</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="0335676cdfde01c2427480e63a96dffe"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-20-725-2024-ie00001.svg" width="64pt" height="10pt" src="os-20-725-2024-ie00001.png"/></svg:svg></span></span> <span class="inline-formula">µ</span>mol kg<span class="inline-formula">⁻¹</span> yr<span class="inline-formula">⁻¹</span> with a detectable increase in the trend in recent years. At the surface during austral winter the oceanic <span class="inline-formula"><i>f</i>CO₂</span> increased at a rate close to or slightly lower than in the atmosphere. To the contrary, in summer, we observed contrasting <span class="inline-formula"><i>f</i>CO₂</span> and dissolved inorganic carbon (C<span class="inline-formula">_<i>T</i>)</span> trends depending on the decade and emphasizing the role of biological drivers on air–sea CO<span class="inline-formula">₂</span> fluxes and pH inter-annual variability. The regional air–sea CO<span class="inline-formula">₂</span> fluxes evolved from an annual source to the atmosphere of 0.8 molC m<span class="inline-formula">⁻²</span> yr<span class="inline-formula">⁻¹</span> in 1985 to a sink of <span class="inline-formula">−0.5</span> molC m<span class="inline-formula">⁻²</span> yr<span class="inline-formula">⁻¹</span> in 2020. Over 1985–2020, the annual pH trend in surface waters of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M26" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.0165</mn><mo>±</mo><mn mathvariant="normal">0.0040</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="88pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="f78ffdaaa34caa0f5eaa9c9ca35bfe50"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-20-725-2024-ie00002.svg" width="88pt" height="10pt" src="os-20-725-2024-ie00002.png"/></svg:svg></span></span> per decade was mainly controlled by the accumulation of anthropogenic CO<span class="inline-formula">₂</span>, but the summer pH trends were modulated by natural processes that reduced the acidification rate in the last decade. Using historical data from November 1962, we estimated the long-term trend for <span class="inline-formula"><i>f</i>CO₂</span>, C<span class="inline-formula">_T</span>, and pH, confirming that the progressive acidification was driven by the atmospheric CO<span class="inline-formula">₂</span> increase. In 59 years this led to a diminution of 11 % for both aragonite and calcite saturation state. As atmospheric CO<span class="inline-formula">₂</span> is expected to increase in the future, the pH and carbonate saturation state will decrease at a faster rate than observed in recent years. A projection of future C<span class="inline-formula">_T</span> concentrations for a high emission scenario (SSP5-8.5) indicates that the surface pH in 2100 would decrease to 7.32 in winter. This is up to <span class="inline-formula">−0.86</span> lower than pre-industrial pH and <span class="inline-formula">−0.71</span> lower than pH observed in 2020. The aragonite undersaturation in surface waters would be reached as soon as 2050 (scenario SSP5-8.5) and 20 years later for a stabilization scenario (SSP2-4.5) with potential impacts on phytoplankton species and higher trophic levels in the rich ecosystems of the Kerguelen Islands area.</p>

Igor Loutsenko, Oksana Yermolayeva

We continue study of equilibrium of two species of 2d coulomb charges (or point vortices in 2d ideal fluid) started in (Igor Loutsenko, J. Phys. A: Math. Gen. 37, 1309, 2004). Although for two species of vortices with circulation ratio -1 the relationship between the equilibria and the factorization/Darboux transformation of the Schrodinger operator was established a long ago, the question about similar relationship for the ratio -2 remained unanswered. Here we present the answer: One has to consider Darboux-type transformations of third order differential operators rather than second order Schrodinger operators. Furthermore, we show that such transformations can also generate equilibrium configurations where an additional charge of a third specie is present. Relationship with integrable hierarchies is briefly discussed.

Áron Varga, Eszter Bihari-Lucena, Márta Ladányi et al.

The goals of the present investigation are to study and to model pale lager beer dealcoholization via reverse osmosis (RO). Samples were dealcoholized at a temperature of 15 ± 1 °C. An Alfa Laval RO99 membrane with a 0.05 m² surface was used. The flux values were measured during the separations. The ethanol content, extract content, bitterness, color, pH, turbidity, and dynamic viscosity of beer and permeate samples were measured. The initial flux values were determined using linear regression. The initial ethanol flux (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>J</mi><mrow><mi>E</mi><mi>t</mi><mi>O</mi><mi>H</mi><mo> </mo><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula>) values were calculated from the initial flux values and the ethanol content values. A 2^P full factorial experimental design was applied, and the factors were as follows: transmembrane pressure (TMP): 10, 20, 30 bar; retentate flow rate (Q): 120, 180, 240 L/h; <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>J</mi><mrow><mi>E</mi><mi>t</mi><mi>O</mi><mi>H</mi><mo> </mo><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula> was considered as the response. The effect sizes of the significant parameters were calculated. The global maximum of the objective function was found using a self-developed Grid Search code. The changes in the analytical parameters were appropriate. The TMP had a significant effect, while the Q had no significant effect on the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>J</mi><mrow><mi>E</mi><mi>t</mi><mi>O</mi><mi>H</mi><mo> </mo><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula>. The effect size of the TMP was 1.20. The optimal value of the factor amounted to TMP = 30 bar. The predicted <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>J</mi><mrow><mi>E</mi><mi>t</mi><mi>O</mi><mi>H</mi><mo> </mo><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula> under the above conditions was 121.965 g/m² h.

Oscar Yáñez-Hernández, Armando Ríos-Lira, Yaquelin Verenice Pantoja-Pacheco et al.

This research presents the increase of the <i>Trichoderma harzianum</i> production process in a biotechnology company. The NOBA (Near-Orthogonal Balanced arrays) method was used to fractionate a mixed-level factorial design to minimize costs and experimentation times. Our objective is to determine the significant factors to maximize the production process of this fungus. The proposed <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mn>2</mn></mrow><mrow><mn>1</mn></mrow></msup><msup><mrow><mn>3</mn></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mn>4</mn></mrow><mrow><mn>2</mn></mrow></msup></mrow></semantics></math></inline-formula> mixed-level design involved five factors, including aeration, humidity, temperature, potential hydrogen (pH), and substrate; the response variable was spore production. The results of the statistical analysis showed that the type of substrate, the air supply, and the interaction of these two factors were significant. The maximization of spore production was achieved by using the breadfruit seed substrate and aeration, while it was shown that variations in pH, humidity, and temperature have no significant impact on the production levels of the fungus.

Kento Sekiguchi, Morimasa Tanimoto, Shuji Fujii

We provide a method for quantifying the kinetics of gelation in milk acidified with glucono-<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>δ</mi></semantics></math></inline-formula>-lactone (GDL) using image analysis techniques, particle image velocimetry (PIV), differential variance analysis (DVA) and differential dynamic microscopy (DDM). The gelation of the milk acidified with GDL occurs through the aggregation and subsequent coagulation of the casein micelles as the pH approaches the isoelectric point of the caseins. The gelation of the acidified milk with GDL is an important step in the production of fermented dairy products. PIV qualitatively monitors the average mobility of fat globules during gelation. The gel point estimated by PIV is in good agreement with that obtained by rheological measurement. DVA and DDM methods reveal the relaxation behavior of fat globules during gelation. These two methods make it possible to calculate microscopic viscosity. We also extracted the mean square displacement (MSD) of the fat globules, without following their movement, using the DDM method. The MSD of fat globules shifts to sub-diffusive behavior as gelation progresses. The fat globules used as probes show the change in matrix viscoelasticity caused by the gelling of the casein micelles. Image analysis and rheology can be used complementarily to study the mesoscale dynamics of the milk gel.

Tongtong Liu, Fuyang Huo, Changqing Ge et al.

A series of novel chromophores A, B, C, and D, based on the julolidinyl donor and the tricyanofuran (TCF) and CF₃-tricyanofuran (CF₃-Ph-TCF) acceptors, have been synthesized and systematically investigated. The <i>3,5</i>-bis(trifluoromethyl)benzene derivative isolation group was introduced into the bridge in the chromophores C and D. These nonlinear optical chromophores showed good thermal stability, and their decomposition temperatures were all above 220 °C. Density functional theory (DFT) was used to calculate the energy gaps and first-order hyperpolarizability (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>β</mi></semantics></math></inline-formula>). The macroscopic electro-optic (EO) activity was measured using a simple reflection method. The highest EO coefficient of poled films containing 35 wt% of chromophore D doped in amorphous polycarbonate afforded values of 54 pm/V at 1310 nm. The results indicate that the <i>3,5</i>-bis(trifluoromethyl)benzene isolation group can suppress the dipole–dipole interaction of chromophores. The moderate <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>r</mi><mrow><mn>33</mn></mrow></msub></mrow></semantics></math></inline-formula> value, good thermal stability, and good yield of chromophores suggest their potential use in the nonlinear optical area.

Miloslav Znojil

An elucidation of the current state of art in quasi-Hermitian quantum theory (QHQT) as inspired by the recent paper by Alase et al (J. Phys. A: Math. Theor. 55 (2022) 244003, paper [1]) is offered. We point out that the author's main discovery (viz., that the QHQT does not extend the standard quantum theory) is not new. In a related comment on the author's method of proof performed in ``the framework of general probabilistic theories'' (GPT) we add that also in this context a few other, mathematically consistent GPT-like theories are already available in the literature (pars pro toto we mention the results using the so called effect algebras). Thirdly, the ``intriguing open question'' about ``what possible constraints, if any, could lead to such a meaningful extension'' is given a tentative answer: The constraint could be just the generalized, non-stationary version of the quasi-Hermiticity.

Yasir Mehmood, Hira Shahid, Md Abdur Rashid et al.

Mesoporous Silica Nanoparticles (MSN) are porous inorganic materials that have been extensively used for drug delivery due to their special qualities, such as biocompatibility, biodegradability, and non-toxicity. MSN is a promising drug delivery system to enhance the efficacy and safety of drug administration in nasal diseases like chronic rhinitis (CR). In this study, we used the sol-gel technique for MSN synthesis and incorporate fluticasone propionate (FP) for intranasal drug administration for the treatment of chronic rhinitis (CR). In order to confirm the particle size, shape, drug release, and compatibility, various instruments were used. MSN was effectively prepared with average sizes ranging between 400 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>±</mo><mo> </mo><mn>34</mn><mrow><mtext> </mtext><mi>nm</mi></mrow></mrow></semantics></math></inline-formula> (mean <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>±</mo><mo> </mo><mi>SD</mi></mrow></semantics></math></inline-formula>) as measured by dynamic light scattering (DLS), while zeta potential verified in all cases their positive charged surface. To investigate MSN features, the Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM), thermal analysis, X-ray diffraction (XRD), and nitrogen adsorption/desorption measurement were used. The loaded compound was submitted to in vitro dissolution tests, and a remarkable dissolution rate improvement was observed compared to the crystalline drug in both pH conditions (1.2 and 7.4 pH). By using an MTT assay cell viability was assessed. The expression levels of the anti-inflammatory cytokines IL-4 and IL-5 were also measured using mRNA extraction from rat blood. Other characterizations like acute toxicity and hemolytic activity were also performed to confirm loaded MSN safety. Loaded MSN was incorporated in nasal spray prepared by using innovator excipients including poloxamer. After this, its nasal spray’s physical characteristics were also determined and compared with a commercial product (Ticovate).

Mirosław Jabłoński

The subject of research is forty dimers formed by imidazol-2-ylidene (I) or its derivative (IR<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>) obtained by replacing the hydrogen atoms in both N-H bonds with larger important and popular substituents of increasing complexity (methyl = Me, <i>iso</i>-propyl = <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mi>i</mi></msup></semantics></math></inline-formula>Pr, <i>tert</i>-butyl = <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mi>t</mi></msup></semantics></math></inline-formula>Bu, phenyl = Ph, mesityl = Mes, 2,6-diisopropylphenyl = Dipp, 1-adamantyl = Ad) and fundamental proton donor (HD) molecules (HF, HCN, H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O, MeOH, NH<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>3</mn></msub></semantics></math></inline-formula>). While the main goal is to characterize the generally dominant C⋯H-D hydrogen bond engaging a carbene carbon atom, an equally important issue is the often omitted analysis of the role of accompanying secondary interactions. Despite the often completely different binding possibilities of the considered carbenes, and especially HD molecules, several general trends are found. Namely, for a given carbene, the dissociation energy values of the IR<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow></mrow><mn>2</mn></msub><mo>⋯</mo></mrow></semantics></math></inline-formula>HD dimers increase in the following order: NH<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>3</mn></msub></semantics></math></inline-formula>< H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O < HCN ≤ MeOH ≪ HF. Importantly, it is found that, for a given HD molecule, IDipp<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula> forms the strongest dimers. This is attributed to the multiplicity of various interactions accompanying the dominant C⋯H-D hydrogen bond. It is shown that substitution of hydrogen atoms in both N-H bonds of the imidazol-2-ylidene molecule by the investigated groups leads to stronger dimers with HF, HCN, H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O or MeOH. The presented results should contribute to increasing the knowledge about the carbene chemistry and the role of intermolecular interactions, including secondary ones.

Carlos Ocampo-López, Álvaro Ospina-Sanjuan, Margarita Ramírez-Carmona et al.

The leaching processes for metals using organic substances represent a sustainable approach to recover precious minerals from solid matrices. However, the generation of organometallic species and the lack of thermodynamic diagrams make it difficult to advance the understanding of their behavior and optimize the process. In this work, a thermodynamically and stoichiometrically consistent mathematical model was developed to estimate the thermodynamic stability of organic substances during the leaching process, and iron leaching with oxalic acid was used as a case study. The Pourbaix and the global thermodynamic stability diagrams for the system were developed in this study. Using a Gaussian^®, it was estimated that the Gibbs free energy formation for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>2</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>2</mn><mrow><mn>1</mn><mo>−</mo></mrow></msubsup><mo>,</mo></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>3</mn><mrow><mn>3</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> was −1407.51, −2308.38, and −3068.89 kcal/mol. A set of eleven independent reactions was formulated for the sixteen species involved in the leaching process, and its stability functions in terms of E_h and pH were calculated to generate a 3D global thermodynamic stability diagram. According to the E_h-pH diagrams for the leaching process, ferrioxalate was identified as the most stable and predominant species in the leaching process at pH above 6.6 under reductive conditions. The mathematical model developed in this work resulted in a thermodynamic tool for predicting leaching processes.

Masao Yoshino, Atsushi Kotaki, Yuui Yokota et al.

The technology to grow single crystals of the required shape directly from a melt has been researched extensively and developed in various industries and research fields. In this study, a micro-pulling-down method and a Mo crucible were applied to the shape-controlled crystal growth of Y<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>3</mn></msub></semantics></math></inline-formula>Al<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>5</mn></msub></semantics></math></inline-formula>O<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>12</mn></msub></semantics></math></inline-formula>:Ce (YAG:Ce). Three types of Mo crucibles with different die shapes were developed. Stable crystal growth of more than 50 mm in length was achieved with the same shape as the die, and scintillation light output of ~20,000 ph/MeV, which is comparable with those of the YAG:Ce crystal grown by Cz method, were obtained. The transmittance of grown crystals above 500 nm was above 70%. The standard deviation (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>σ</mi></semantics></math></inline-formula>) of the scintillation light output at each position of the 50-mm-long sample was found to be within ±16%.

Tirtha Raj Acharya, Geon Joon Lee, Eun Ha Choi

Citrate-capped silver nanoparticles (<i>Ag@Cit NPs</i>) were synthesized by a simple plasma-assisted reduction method. Homogenous colloidal <i>Ag@Cit NPs</i> solutions were produced by treating a <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">A</mi><mi mathvariant="normal">g</mi><mi mathvariant="normal">N</mi><msub><mi mathvariant="normal">O</mi><mn>3</mn></msub></mrow></semantics></math></inline-formula>-trisodium citrate-deionized water with an atmospheric-pressure argon plasma jet. The plasma-synthesized <i>Ag@Cit NPs</i> exhibited quasi-spherical shape with an average particle diameter of about 5.9−7.5 nm, and their absorption spectra showed surface plasmon resonance peaks at approximately 406 nm. The amount of <i>Ag@Cit NPs</i> increased in a plasma exposure duration-dependent manner. Plasma synthesis of <i>Ag@Cit NPs</i> was more effective in the 8.5 cm plume jet than in the shorter and longer plume jets. A larger amount of <i>Ag@Cit NPs</i> were produced from the 8.5 cm plume jet with a higher pH and a larger number of aqua electrons, indicating that the synergetic effect between plasma electrons and citrate plays an important role in the plasma synthesis of <i>Ag@Cit NPs</i>. Plasma-assisted citrate reduction facilitates the synthesis of <i>Ag@Cit NPs</i>, and citrate-capped nanoparticles are stabilized in an aqueous solution due to their repulsive force. Next, we demonstrated that plasma-synthesized <i>Ag@Cit NPs</i> exhibited a significant degradation of methylene blue dye.

M. P. Hemming, J. Kaiser, J. Boutin et al.

<p>The Mediterranean Sea comprises just 0.8 % of the global oceanic surface, yet considering its size, it is regarded as a disproportionately large sink for anthropogenic carbon due to its physical and biogeochemical characteristics. An underwater glider mission was carried out in March–April 2016 close to the BOUSSOLE and DyFAMed time series moorings in the northwestern Mediterranean Sea. The glider deployment served as a test of a prototype ion-sensitive field-effect transistor pH sensor. Dissolved oxygen (O<span class="inline-formula">₂</span>) concentrations and optical backscatter were also observed by the glider and increased between 19 March and 1 April, along with pH. These changes indicated the start of a phytoplankton spring bloom, following a period of intense mixing. Concurrent measurements of CO<span class="inline-formula">₂</span> fugacity and O<span class="inline-formula">₂</span> concentrations at the BOUSSOLE mooring buoy showed fluctuations, in qualitative agreement with the pattern of glider measurements. Mean net community production rates (<span class="inline-formula"><i>N</i></span>) were estimated from glider and buoy measurements of dissolved O<span class="inline-formula">₂</span> and inorganic carbon (DIC) concentrations, based on their mass budgets. Glider and buoy DIC concentrations were derived from a salinity-based total alkalinity parameterisation, glider pH and buoy CO<span class="inline-formula">₂</span> fugacity. The spatial coverage of glider data allowed the calculation of advective O<span class="inline-formula">₂</span> and DIC fluxes. Mean <span class="inline-formula"><i>N</i></span> estimates for the euphotic zone between 10 March and 3 April were (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">17</mn><mo>±</mo><mn mathvariant="normal">36</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="46pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="72722262efff25e0f14c9d145645b397"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-18-1245-2022-ie00001.svg" width="46pt" height="10pt" src="os-18-1245-2022-ie00001.png"/></svg:svg></span></span>) for glider O<span class="inline-formula">₂</span>, (<span class="inline-formula">44±94</span>) for glider DIC, (<span class="inline-formula">17±37</span>) for buoy O<span class="inline-formula">₂</span> and (<span class="inline-formula">49±86</span>) <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">mmol</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">d</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="67pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="e2e1b050bb1cf0596ed782afacc19a6e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-18-1245-2022-ie00002.svg" width="67pt" height="13pt" src="os-18-1245-2022-ie00002.png"/></svg:svg></span></span> for buoy DIC, all indicating net metabolic balance over these 25 d. However, these 25 d were actually split into a period of net DIC increase and O<span class="inline-formula">₂</span> decrease between 10 and 19 March and a period of net DIC decrease and O<span class="inline-formula">₂</span> increase between 19 March and 3 April. The latter period is interpreted as the onset of the spring bloom. The regression coefficients between O<span class="inline-formula">₂</span> and DIC-based <span class="inline-formula"><i>N</i></span> estimates were 0.25 <span class="inline-formula">±</span> 0.08 for the glider data and 0.54 <span class="inline-formula">±</span> 0.06 for the buoy, significantly lower than the canonical metabolic quotient of <span class="inline-formula">1.45±0.15</span>. This study shows the added value of co-locating a profiling glider with moored time series buoys, but also demonstrates the difficulty in estimating <span class="inline-formula"><i>N</i></span>, and the limitations in achievable precision.</p>

J. Li, J. Li, L. Cao et al.

<p>For the first time in the North China Plain (NCP) region, we investigated the seasonal variations in submicron particles (NR-PM<span class="inline-formula">₁</span>) and their chemical composition at a background mountainous site of Xinglong using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer. The average concentration of NR-PM<span class="inline-formula">₁</span> was highest in autumn (15.1 <span class="inline-formula">µg m⁻³</span>) and lowest in summer (12.4 <span class="inline-formula">µg m⁻³</span>), with a greater abundance of nitrate in spring (34 %), winter (31 %) and autumn (34 %) and elevated organics (40 %) and sulfate (38 %) in summer. PM<span class="inline-formula">₁</span> in Xinglong showed higher acidity in summer and moderate acidity in spring, autumn and winter, with average pH values of <span class="inline-formula">2.7±0.6</span>, <span class="inline-formula">4.2±0.7</span>, <span class="inline-formula">3.5±0.5</span> and <span class="inline-formula">3.7±0.6</span>, respectively, which is higher than those estimated in the United States and Europe. The size distribution of all PM<span class="inline-formula">₁</span> species showed a consistent accumulation mode peaking at approximately 600–800 nm (<span class="inline-formula"><i>d</i>_va</span>), indicating a highly aged and internally mixed nature of the background aerosols, which was further supported by the source appointment results using positive matrix factorization and multilinear engine analysis. Significant contributions of aged secondary organic aerosol (SOA) in organic aerosol (OA) were resolved in all seasons (<span class="inline-formula">&gt;77</span> %), especially in summer. The oxidation state and the process of evolution of OAs in the four seasons were further investigated, and an enhanced carbon oxidation state (<span class="inline-formula">−0.45</span>–0.10) and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M14" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">O</mi><mo>/</mo><mi mathvariant="normal">C</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="25pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="f616bfb5e1a3a5078e43c0f49090c8c8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-4521-2021-ie00001.svg" width="25pt" height="14pt" src="acp-21-4521-2021-ie00001.png"/></svg:svg></span></span> (0.54–0.75) and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">OM</mi><mo>/</mo><mi mathvariant="normal">OC</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="42pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="6f44622039593675583191a6fe29e912"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-4521-2021-ie00002.svg" width="42pt" height="14pt" src="acp-21-4521-2021-ie00002.png"/></svg:svg></span></span> (1.86–2.13) ratios – compared with urban studies – were observed, with the highest oxidation state appearing in summer, likely because of the relatively stronger photochemical processing that dominated the formation processes of both less oxidized OA (LO-OOA) and more oxidized OA (MO-OOA). Aqueous-phase processing also contributed to the SOA formation and prevailed in winter, with the share to MO-OOA being more important than that to LO-OOA. In addition, regional transport also played an important role in the variations in SOA. Especially in summer, continuous increases in SOA concentration as a function of odd oxygen (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M16" display="inline" overflow="scroll" dspmath="mathml"><mrow><mrow class="chem"><msub><mi mathvariant="normal">O</mi><mi>x</mi></msub></mrow><mo>=</mo><mrow class="chem"><msub><mi mathvariant="normal">O</mi><mn mathvariant="normal">3</mn></msub></mrow><mo>+</mo><mrow class="chem"><msub><mi mathvariant="normal">NO</mi><mn mathvariant="normal">2</mn></msub></mrow></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="74pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="802ea3f5690373479ac6f047b3c76472"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-4521-2021-ie00003.svg" width="74pt" height="13pt" src="acp-21-4521-2021-ie00003.png"/></svg:svg></span></span>) were found to be associated with the increases in wind speed. Furthermore, backward trajectory analysis showed that higher concentrations of submicron particles were associated with air masses transported short distances from the southern regions in all four seasons, while long-range transport from Inner Mongolia (western and northern regions) also contributed to summertime particulate pollution in the background areas of the NCP. Our results illustrate that the background particles in the NCP are influenced significantly by aging processes and<span id="page4522"/> regional transport, and the increased contribution of aerosol nitrate highlights how regional reductions in nitrogen oxide emissions are critical for remedying occurrence of nitrate-dominated haze events over the NCP.</p>

M. A. Battaglia Jr., M. A. Battaglia Jr., N. Balasus et al.

<p>Particle acidity (aerosol pH) is an important driver of atmospheric chemical processes and the resulting effects on human and environmental health. Understanding the factors that control aerosol pH is critical when enacting control strategies targeting specific outcomes. This study characterizes aerosol pH at a land–water transition site near Baltimore, MD, during summer 2018 as part of the second Ozone Water-Land Environmental Transition Study (OWLETS-2) field campaign. Inorganic fine-mode aerosol composition, gas-phase <span class="inline-formula">NH₃</span> measurements, and all relevant meteorological parameters were used to characterize the effects of temperature, aerosol liquid water (ALW), and composition on predictions of aerosol pH. Temperature, the factor linked to the control of <span class="inline-formula">NH₃</span> partitioning, was found to have the most significant effect on aerosol pH during OWLETS-2. Overall, pH varied with temperature at a rate of <span class="inline-formula">−</span>0.047 <span class="inline-formula">K⁻¹</span> across all observations, though the sensitivity was <span class="inline-formula">−</span>0.085 <span class="inline-formula">K⁻¹</span> for temperatures <span class="inline-formula">&gt;</span> 293 <span class="inline-formula">K</span>. ALW had a minor effect on pH, except at the lowest ALW levels (<span class="inline-formula">&lt;</span> 1 <span class="inline-formula">µg m⁻³</span>), which caused a significant increase in aerosol acidity (decrease in pH). Aerosol pH was generally insensitive to composition (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">SO</mi><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="29pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="815783a157bc15e547bdd7a24388d96b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-18271-2021-ie00001.svg" width="29pt" height="17pt" src="acp-21-18271-2021-ie00001.png"/></svg:svg></span></span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M12" display="inline" overflow="scroll" dspmath="mathml"><mrow><mrow class="chem"><msubsup><mi mathvariant="normal">SO</mi><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow><mo>:</mo><mrow class="chem"><msubsup><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="cf5b1b8a68e95e817603fea50cdf8bb1"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-18271-2021-ie00002.svg" width="58pt" height="17pt" src="acp-21-18271-2021-ie00002.png"/></svg:svg></span></span>, total <span class="inline-formula">NH₃</span> (Tot-<span class="inline-formula">NH₃</span>) <span class="inline-formula">=</span> <span class="inline-formula">NH₃</span> <span class="inline-formula">+</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M18" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="24pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="7b888eb222795ca6a6dd2ceb535b59a0"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-18271-2021-ie00003.svg" width="24pt" height="15pt" src="acp-21-18271-2021-ie00003.png"/></svg:svg></span></span>), consistent with recent studies in other locations. In a companion paper, the sources of episodic <span class="inline-formula">NH₃</span> events (95th percentile concentrations, <span class="inline-formula">NH₃</span> <span class="inline-formula">&gt;</span> 7.96 <span class="inline-formula">µg m⁻³</span>) during the study are analyzed; aerosol pH was higher by only <span class="inline-formula">∼</span> 0.1–0.2 <span class="inline-formula">pH</span> units during these events compared to the study mean. A case study was analyzed to characterize the response of aerosol pH to nonvolatile cations (NVCs) during a period strongly influenced by primary Chesapeake Bay emissions. Depending on the method used, aerosol pH was estimated to be either weakly (<span class="inline-formula">∼</span> 0.1 <span class="inline-formula">pH</span> unit change based on <span class="inline-formula">NH₃</span> partitioning calculation) or strongly (<span class="inline-formula">∼</span> 1.4 <span class="inline-formula">pH</span> unit change based on ISORROPIA thermodynamic model predictions) affected by NVCs. The case study suggests a strong pH gradient with size during the event and underscores the need to evaluate assumptions of aerosol mixing state applied to pH calculations. Unique features of this study, including the urban land–water transition site and the strong influence of <span class="inline-formula">NH₃</span> emissions from both agricultural and industrial sources, add to the understanding of aerosol pH and its controlling factors in diverse environments.</p>

Zhanyi Xiang, Yifei Jing, Hidekazu Ikezaki et al.

The lipid phosphoric acid di-n-decyl ester (PADE) has played an important role in the development of taste sensors. As previously reported, however, the concentration of PADE and pH of the solution affected the dissociation of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi mathvariant="normal">H</mi><mo>+</mo></msup></mrow></semantics></math></inline-formula>, which made the measurement results less accurate and stable. In addition, PADE caused deterioration in the response to bitterness because PADE created the acidic environment in the membrane. To solve these problems, our past study tried to replace the PADE with a completely dissociated substance called tetrakis [3,5-bis (trifluoromethyl) phenyl] borate sodium salt dehydrate (TFPB) as lipid. To find out whether the two substances can be effectively replaced, it is necessary to perform an in-depth study on the properties of the two membranes themselves. In this study, we fabricated two types of membrane electrodes, based on PADE or TFPB, respectively, using 2-nitrophenyl octyl ether (NPOE) as a plasticizer. We measured the selectivity to cations such as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mi>Cs</mi></mrow><mo>+</mo></msup></mrow></semantics></math></inline-formula>,<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mrow><mtext> </mtext><mi mathvariant="normal">K</mi></mrow></mrow><mo>+</mo></msup></mrow></semantics></math></inline-formula>,<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mrow><mtext> </mtext><mi>Na</mi></mrow></mrow><mo>+</mo></msup></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mi>Li</mi></mrow><mo>+</mo></msup></mrow></semantics></math></inline-formula>, and also the membrane impedance of the membranes comprising PADE or TFPB of the different concentrations. As a result, we found that any concentration of PADE membranes always had low ion selectivity, while the ion selectivity of TFPB membranes was concentration-dependent, showing increasing ion selectivity with the TFPB concentrations. The ion selectivity order was <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mi>Cs</mi></mrow><mo>+</mo></msup><mo>></mo><msup><mi mathvariant="normal">K</mi><mo>+</mo></msup><mo>></mo><msup><mrow><mi>Na</mi></mrow><mo>+</mo></msup><mo>></mo><msup><mrow><mi>Li</mi></mrow><mo>+</mo></msup></mrow></semantics></math></inline-formula>. The hydration of ions was considered to participate in this phenomenon. In addition, the membrane impedance decreased with increasing PADE and TFPB concentrations, while the magnitudes differed, implying that there is a difference in the dissociation of the two substances. The obtained results will contribute to the development of novel receptive membranes of taste sensors.